add RunPipe()

checkout.go

@@ -81,7 +81,11 @@ func (repo *Repo) checkoutBranch(bName string) bool {
 func (repo *Repo) createUserBranch(branch string) error {
 	if branch == "" {
 		// get the username here?
-		return fmt.Errorf("gitpb createuserBranch() logic err. git branch name can not be blank")
+		usr, err := user.Current()
+		if err != nil {
+			return err
+		}
+		branch = usr.Username
 	}
 	if repo.IsDirty() {
 		// never change repos on dirty branches

shell.go

@@ -1,9 +1,11 @@
 package gitpb
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -185,3 +187,70 @@ func (repo *Repo) CountDiffObjects(branch1, branch2 string) int {
 	// log.Info("countDiffObjects()", cmd, len(r.Stdout), strings.Join(r.Stdout, " "))
 	return len(r.Stdout)
 }
+
+func (repo *Repo) RunPipe(cmd1 []string, cmd2 []string) cmd.Status {
+	var s cmd.Status
+	var arg0 string
+	var args []string
+	if len(cmd1) == 0 {
+		s.Error = errors.New("Error: Command slice is empty.")
+		return s
+	}
+	if len(cmd1) == 1 {
+		// Pass the first element as the command, and the rest as variadic arguments
+		arg0 = cmd1[0]
+	} else {
+		arg0 = cmd1[0]
+		args = cmd1[1:]
+	}
+	cmdShow := exec.Command(arg0, args...)
+	cmdShow.Dir = repo.GetFullPath()
+
+	if len(cmd2) == 0 {
+		s.Error = errors.New("Error: Command slice is empty.")
+		return s
+	}
+	if len(cmd2) == 1 {
+		// Pass the first element as the command, and the rest as variadic arguments
+		arg0 = cmd2[0]
+	} else {
+		arg0 = cmd2[0]
+		args = cmd2[1:]
+	}
+	// 2. Create the command to calculate the patch-id from stdin.
+	cmdPipeID := exec.Command(arg0, args...)
+	cmdPipeID.Dir = repo.GetFullPath()
+
+	// 3. Connect the output of "git show" to the input of "git patch-id".
+	//    This is the Go equivalent of the shell pipe `|`.
+	pipe, err := cmdShow.StdoutPipe()
+	if err != nil {
+		s.Error = fmt.Errorf("failed to create pipe: %w", err)
+		return s
+	}
+	cmdPipeID.Stdin = pipe
+
+	// 4. We need a buffer to capture the final output from git patch-id.
+	var output bytes.Buffer
+	cmdPipeID.Stdout = &output
+
+	// 5. Start the reading command (patch-id) first.
+	if err := cmdPipeID.Start(); err != nil {
+		s.Error = fmt.Errorf("failed to start git-patch-id: %w", err)
+		return s
+	}
+
+	// 6. Run the writing command (show). This will block until it's done.
+	if err := cmdShow.Run(); err != nil {
+		s.Error = fmt.Errorf("failed to run git-show: %w", err)
+		return s
+	}
+
+	// 7. Wait for the reading command to finish.
+	if err := cmdPipeID.Wait(); err != nil {
+		s.Error = fmt.Errorf("failed to wait for git-patch-id: %w", err)
+		return s
+	}
+
+	return s
+}